Production: Forage Analysis Basics

Does your forage testing lab make the grade?

Forage testing is essential if you want to manage for higher production and efficiency. But what should you expect from your forage testing lab? Ralph Ward, president of Cumberland Valley Analytical Services, one of the largest forage testing labs in the U.S., offers these insights.

What should you expect from a forage testing lab?

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"Laboratories are expected to accurately evaluate diverse feeds for nutrients and characteristics that can be difficult to execute," Ward says. "Choose a lab that will work with you to meet your expectations and those of your nutritionist. A dairy producer should look for a forage testing lab that can provide solutions, not just numbers. You want someone who’ll work for you."

Good labs offer responsiveness, transparency, a staff that understands ruminant nutrition and agronomic concepts, and full service. They should also be innovative and connected with industry.

What are the most common mistakes in forage and feedstuff testing?

While producers perceive that forage laboratories often get it wrong, the greatest source of error in forage testing relates to obtaining a representative sample for submission to the lab, Ward says.

Beyond that, the greatest source of error in the lab is connected to sample preparation. "Subsampling, dry-down and reduction of particle size in a manner that maintains sample homogeneity are areas of potential error," he says.

Another common error is when a specific sample procedure is not valid for the feed matrix. Labs get a lot of unusual samples, such as food byproducts. Applying the correct procedure is critical. The first step in that process is to have the sample properly identified.

How often should you test your forages?

There are no hard and fast rules here, but "you need to test frequently enough to capture and define variation in a feed or forage source," Ward says.

For example, a bunker of corn silage that’s very consistent may not need to be tested as frequently as a bunker of hay silage where there’s a lot of variation and rapid use.

"In a large herd of 2,000 or more cows, where you’re rapidly going through forage material, you may need to test several times per week to capture variation," he says. "In smaller herds with consistent forages, two times per month may be adequate."

Where’s forage testing headed?

"We’ve seen tremendous change in the level of information requested," Ward says. "Technology requirements have been ramped up, and we need more sophisticated approaches."

In the future, he projects that additional nutrients will be considered in forage testing. Among them is likely to be aNDFom (Neutral Detergent Fiber [NDF], on an organic matter or ash-free basis) and indigestible NDF.

There will also be more use of Near Infrared Reflectance (NIR) technology as a qualitative tool, especially for nitrate and toxin identification.

"NIR testing in recent years has seen widespread acceptance with improvements in calibrations and application," Ward explains.

"However, there are applications for forage characterization and quality control processes that have not even been considered," he adds.